Windsheild wont turn off!

My wife was driving my truck (2004 Avalanche) on the other day and it started to rain. She called me and said the windshield wipers can't turn off. I checked the wipers when she made it back home and the wipers work on the hi and standard speeds only. The delay don't work at all. I took out the fuse to stop the things from moving while I drove on the next day (LOL). What do I need to do to repair the issue. Thanks.